Shivani Amin

Why are my teeth sensitive? Causes and prevention of tooth sensitivity

Having sensitive teeth can be extremely annoying, especially when you’re enjoying an ice-cold drink. It might be delicious and refreshing…but when it hits your teeth…ouch. 🥶

What causes your teeth to be sensitive?

Your teeth are made up of enamel and dentine. The enamel is the super strong stuff that comprises the outer layer of the tooth and has the job of protecting it. It is fairly thick on the biting surfaces (around 2mm) but on the side portion, it can be as thin as 0.3mm.

The internal portion of the tooth is made up of dentine. This forms the bulk of the tooth and is a lot softer than enamel. The dentine has millions of tubes running through it which contain fluid. They are called dentinal tubules and they directly communicate with nerves that innervate the tooth. When something touches these tubules, it causes movement of fluid within them; they then transmit to the nerve, causing you to feel pain/sensitivity.

This means that if your enamel wears away, leaving your dentine exposed, you may be at risk of sensitivity.


What causes dentine exposure?

Enamel loss is the main cause of dentine exposure. This can be caused by many different things, including:

  • Acid beverages that erode the teeth away. The higher the strength of the acidic beverages, and the more frequently you consume them, the more erosion you will get. If you think your daily habit of a glass of orange juice is not harmful, think again. Orange juice is around pH 3, which means that it’s 10,000 times stronger than water. If this is a habit you have, you risk doing a lot of damage to your teeth.
  • Tooth grinding will wear your enamel away quickly.
  • Chipped teeth will expose the inner dentine part of your tooth as well.
  • Gum recession exposes the root surface of your tooth. This is particularly bad as the root surface does not have the protective enamel coating, so straight away it’s susceptible to sensitivity.


How do you treat tooth sensitivity?

The main way to stop the movement of fluids is to create a barrier at the end of the tubules i.e. block the entrance of the tubules by covering them with something. This can be done in a variety of ways. The other way to treat the issue is to desensitise the nerve, which can be achieved by using a special type of toothpaste.


Toothpastes for sensitive teeth

Now the thing to remember here is that all the toothpastes work in a slightly different way and it’s hard to say 100% that they will work for you. The best thing to do is to try one for a couple of weeks and if it works for you then great. If not, try the next one on the list. Here is a list of some of the common toothpastes our patients try.


Colgate Sensitive Pro-Relief

Colgate Sensitive Pro-ReliefColgate Sensitive Pro-Relief mouth wash

This contains Arginine 8% which works by sealing the dentinal tubules. Colgate also have a mouthwash that helps to treat sensitivity.


Sensodyne Daily Care Original

Sensodyne Daily Care Original

This also works by blocking the tubules.


Sensodyne Repair and Protect

Sensodyne Repair and Protect




This works by blocking the tubules using Calcium Sodium Phosphosilicate, which Sensodyne has branded as NovaMin®.


These are just a few examples of desensitising toothpastes available. Sensodyne alone has over a dozen types and it would be difficult to explain the differences in a blog like this. The take home message is that there are many different types of toothpaste, which work in different ways. There is generally no one toothpaste that works better than another and different ones works for different people. So as suggested, try some out and stick with whichever works best for you.


What can your dentist do for you?

Dentists are able to use medicaments that are not available over the counter and they may benefit your type of sensitivity. Some of the common ones used are:

  1. High strength fluoride varnish

This blocks the tubules just like the toothpaste mentioned above. Normal toothpaste will have a fluoride concentration of 1450ppm. Fluoride varnish is a lot stronger. The type we use contains 22,600ppm.

  1. Dentine sealants

These work just like the rest of the other desensitising agents do – they seal the tubules. You apply a thin layer of this liquid and it rapidly seals everything up.

  1. Cover the exposed parts of dentine with a filling

If you want to be 100% sure that the tubules are fully sealed then the best thing to use is a composite resin. This substance is tooth coloured and blends in extremely well to your teeth so it is a completely natural looking solution.


If you’d like to discuss tooth sensitivity with a dentist, call 020 3925 3846, email or fill in our form and we will get back to you.